I. Field of the Invention
The present invention relates generally to microwave lenses and, more particularly, to a microwave lens constructed of a metamaterial and with a MEMS device to vary the resonant frequency of the lens.
II. Description of Related Art
The use of metamaterial in microwave applications, such as automotive radar systems, continues to expand. Such metamaterials exhibit properties in response to incident electromagnetic radiation which vary as a function of the shape of the metamaterial rather than the composition of the metamaterial.
Conventionally, the metamaterial comprises a plurality of inductor-capacitor (LC) cells that are arranged in an array. Often the array is planar and a plurality of arrays are stacked one upon each other to form the microwave lens.
Each cell in the array forms an LC resonator which resonates in response to incident electromagnetic radiation at frequencies which vary as a function of the shape of the LC cell. As such, the microwave lens may be utilized to focus, defocus, steer or otherwise control a beam of microwave electromagnetic radiation directed through the lens.
One disadvantage of the previously known microwave lenses using metamaterials, however, is that the resonant frequency of the metamaterial, and thus of the lens, is fixed. In many situations, however, it would be useful to vary the resonant frequency of the lens.